From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Wiring issues and solutions for the Smith electric petrol gauge.
| Identifier | ExFiles\Box 61\3\ scan0339 | |
| Date | 30th September 1932 | |
| X4523 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wst. c. EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Wst.1/AD30.9.32. SMITH ELECTRIC PETROL GAUGE CONNECTIONS. We have had complaints made to us that owing to the fact of the Smith electric petrol gauge connection being made to the ignition tubes on the distribution board, if ever a fault occurs on the petrol gauge the ignition is cut off. Two such failures have already been recorded, one in London and one in the Test Dept. and we suggest that the connection to the petrol gauge be connected to the dynamo fuse (No.1) instead of the ignition fuse. The petrol gauge would then be switched on whenever the switch was put through the I & C position and not the I position. In the event of a fault occurring in the petrol gauge circuit only the dynamo charge would be cut off and we think this would be, for a customer, the lesser of two evils. Alternatively, it might be worth while to connect the petrol gauge from the Klaxon horn terminal on the distribution board (No.6) and take the wire through a small press button on the instrument board as is usually done on aircraft. To read the amount of petrol in the tank it would then be necessary to press the small button and the whole of the petrol gauge circuit would be normally dead. We should be glad to have your views on the matter. Hs{Lord Ernest Hives - Chair}/Wst. P.S. We have since discovered that this scheme of using a press button for the petrol gauge could be conveniently be accomodated in the instrument board light press button circuit on the switch-box. Hs{Lord Ernest Hives - Chair}/Wst. | ||